Making a mash tun, need some advice...

So I've started to make a mash tun from a 48 qt rubbermaid cooler, however I'm having trouble finding either flange nuts or washers that would work well to put up against the wall of the cooler - the wall isn't flush, so when I try to put a washer in there, there's a gap. The nipple pipe thingy fits relatively snug, so I was thinking about using epoxy to secure it in the hole in the cooler, and then putting a layer of silicone over the epoxy to waterproof it. This way, the nipple pipe would be permanently in the tun, but I would be able to remove the compression to the manifold as well as the ball valve on the other side. Has anyone had any experience with this?

Also, I've been reading that with a cooler this big that sometimes the grain bed isn't all that deep for a 5 gal batch. Would it make more sense to do 10 gal. batches with this setup (I was thinking doing a 6 gal boil from the sparge and splitting it into 2 fermenters and bringing them up to 5 gal. each).

Thanks, I'm getting pretty excited about moving to all grain:rockin:

It's difficult to picture what you are talking about without a photo, but would an O-ring work between the cooler wall and a washer?

As for your grain bed, if the grain is not very deep, you don't get as much of a filter effect, but you do have less chance for stuck sparges. So, I suppose it's a trade-off. I don't think you would have to do 10 gal. batches, but I imagine you will certainly have room in a cooler that big.

XCMerk22 said:

Also, I've been reading that with a cooler this big that sometimes the grain bed isn't all that deep for a 5 gal batch. Would it make more sense to do 10 gal. batches with this setup (I was thinking doing a 6 gal boil from the sparge and splitting it into 2 fermenters and bringing them up to 5 gal. each).

Thanks, I'm getting pretty excited about moving to all grain:rockin:

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If you're going to be batch sparging, then grainbed depth isn't really much of an issue, and bigger MLTs are good because batch sparging require room for extra water in addition to the grains.

Your boil volume sentence is a little confusing: for 5 gallon batches, you will be boiling more like 6.5-7 gallons of wort. If I were you, I wouldn't *plan* to boil down and top up to volume. (It happens sometimes, but I wouldn't do it on purpose: I think it leads to darker and more carmelized tasting beers, and one of the reasons for doing AG is to avoid that.)

Since your MLT is plenty big, you might be able to up your routine batch size. I usually do 6 gallon batches. I primary in a bucket and 6 gals fits just fine. (It's usually a little less than 6 gals.) And by the time you leave the trub behind in primary, it'll still fit (barely) in a 5 gal carboy secondary. Or yeah, you could do 10 gal batches and split it up.

For the o-ring between the washer and the wall of the cooler I used garden hose washers. They are a snug fit on a half inch nipple, but they do work.

Al

Here's a schematic of what it looks like (I'm at work so I can't take a pic).



Is there anywhere I can get a washer and O-ring to put around the 1/2 inch nipple? I checked out home depot and the local hardware store, but all I could find as far as washers go are ones that are about 4 inches in diameter, so they seem a little too big to form a good seal with the O-ring.

I tried every washer I could find, and mine still leaked...until I bought one of these:
http://www.austinhomebrew.com/product_info.php?cPath=178_33_82_89&products_id=10057

It has been fine since.

That looks like it would work great, except that it's 7/8" and my cooler has a 1/2" spigot hole

Well it just so happens (if I understand your dilemma) I JUST went through the same trouble with my MLT that I built. It's a 48qt Coleman rectangular cooler. I built a manifold out of 1/2" copper tubing. I had a BI**H of a time getting a seal at the nipple/inner wall and having it not leak.

Here is what I ultimately did and it seems to be holding up (I will be doing my first AG this weekend so we'll see). I took one of those large washers that you are talking about and ground it flat on one side so that it would fit under the nipple and floor of the cooler. I used a hand made gasket/washer from a piece of rubber flap used for pluming in toilets. I cut the piece of rubber to act as a washer/gasket. It seems to be working.

Good luck!

I have a 52L coleman rectangular and suffered the same problem. I found I could make a really great o-ring by custom carving up and drilling a standard #10 bung. No leaks at all and I've done about 10 AG batches now.

Thanks for all the great replies. Forgive my ignorance, but what is a bung? I'm picturing it's similar to a stopper.

XCMerk22 said:

Thanks for all the great replies. Forgive my ignorance, but what is a bung? I'm picturing it's similar to a stopper.

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You are correct. Typically they have a hole in them.

Awesome, I just found a pack of #8 stoppers in my lab, time to start carving!

Yeah with mine, the hole is just above the cusp where the wall of the cooler meets the floor. A real pain to get a good seal, but it's do-able.